The present invention relates to a positioner system for controlling a fluid control valve and, more particularly, to an intelligent positioner system and software routines for controlling the operation thereof.
Fluid control valves are used to control the transmission and distribution of fluids, such as liquids and gases. In such applications there often are requirements for highly reliable and accurate valves for proper performance. However, due to the physical performance of the valve, as well as the environment in which the valve operates, periodic maintenance, calibration and adjustment of the valve must be maintained throughout its operation. Furthermore, the valve can exhibit non-linear and seemingly unpredictable behavior. For example, high friction in the valve may cause stick-slip behavior when the valve is being adjusted between an open and closed position. In addition, ambient temperatures and aging affect component characteristics and cause position errors.
Many valves are fitted with actuators and positioners to control the valve movement. Furthermore, some positioners are computer controlled. However, such control has been somewhat limited. In addition, the conventional computer-controlled positioners do not adequately predict actual valve behavior. Therefore what is needed is a valve positioner that facilitates the continuous maintenance, calibration and adjustment requirements of the valve.